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United States Patent |
5,624,280
|
Kato
|
April 29, 1997
|
Branch joint box accommodating bus bars and bus bar blank
Abstract
A branch joint box includes upper and lower casings of an identical shape
which form a casing assembly by overturning one of the upper and lower
casings. First connector portions and second connector portions are
arranged in a plurality of rows and having first terminal holes and second
terminal holes, respectively. Bus bars each have a coupling portion
accommodated in the casing assembly and first and second terminal portions
extend from opposite sides of the coupling portion, respectively, and
project out of the first and second terminal holes, respectively. The
upper and lower casings have first and second locking portions engageable
with each other and are disposed at one side of the first and second
connector portions, respectively. Each of the upper and lower casings has
a protrusion formed on one outer side face adjacent to the other side of
each of the first and second connector portions such that a pitch from a
distal end of the protrusion to a corresponding outermost one of the first
and second terminal holes coincides with a pitch from the other outer side
face of each of the upper and lower casings to a corresponding outermost
one of the first and second terminal holes such that the first and second
terminal holes are disposed symmetrically in alignment with each other.
Inventors:
|
Kato; Shinshu (Yokkaichi, JP)
|
Assignee:
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Sumitomo Wiring Systems, Ltd. (Yokkaichi, JP)
|
Appl. No.:
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327785 |
Filed:
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October 20, 1994 |
Foreign Application Priority Data
Current U.S. Class: |
439/724; 439/212 |
Intern'l Class: |
H01R 011/09 |
Field of Search: |
439/724,212,213,701,709,712,76.2
|
References Cited
U.S. Patent Documents
5160274 | Nov., 1992 | Ozaki et al.
| |
5207591 | May., 1993 | Ozaki et al.
| |
5295847 | Mar., 1994 | Ozaki et al.
| |
5295858 | Mar., 1994 | Kasai et al.
| |
5322445 | Jun., 1994 | Ozaki | 439/212.
|
5490794 | Feb., 1996 | Kobayashi et al. | 439/212.
|
Primary Examiner: Nguyen; Khiem
Assistant Examiner: Kim; Yong
Attorney, Agent or Firm: Greenblum & Bernstein P.L.C.
Claims
What is claimed is:
1. A bus bar blank comprising:
a plurality of bus bars which are arranged in a plurality of rows in a
longitudinal direction of the bus bar blank, a plurality of pairs of first
and second terminal portions in each bus bar extending longitudinally
symmetrically in opposite directions from a laterally extending coupling
portion, respectively, at a predetermined lateral interval;
first and second carrier portions which are, respectively, coupled with
opposite lateral sides of the coupling portion of each of the bus bars;
wherein first and second terminal portions of the bus bars of even rows
project into regions into which first and second terminal portions of the
bus bars of odd rows do not project;
wherein the first and second terminal portions of the bus bars of odd rows
are aligned with each other and the first and second terminal portions of
the bus bars of even rows are aligned with each other such that the bus
bar blank can be subjected to sequential feed during continuous process
working.
2. A bus bar blank as claimed in claim 1, wherein a width of each of the
first and second carrier portions is increased such that a cutting line
for separating each of the bus bars from the bus bar blank in each of the
first and second carrier portions is set in a shape of a hook from a rear
end position of the coupling portion of a front one of neighboring bus
bars to a front end portion of the coupling portion of a rear one of the
neighboring bus bars, such that cut distal ends of each of the first and
second carrier portions project beyond the first and second terminal
portions of the neighboring bus bars.
Description
BACKGROUND OF THE INVENTION
The present invention generally relates to a branch joint box in which bus
bars are accommodated and a bus bar blank and more particularly, to a
branch joint box in which coupling portions of the bus bars are
accommodated in a casing assembly formed by upper and lower casings of an
identical shape by overturning one of the upper and lower casings upside
down and upper and lower terminal portions extending from opposite sides
of the coupling portions are projected out of terminal holes of connector
portions of the upper and lower casings, respectively such that the upper
and lower terminal portions extend symmetrically in alignment with each
other and a bus bar blank from which a plurality of bus bar sets each
having a plurality of the bus bars can be taken efficiently.
A number of bus bars are accommodated in a branch joint box provided in the
course of wiring harnesses for a motor vehicle so as to perform connection
and branching of an electric circuit and terminals provided on the bus
bars are projected out of terminal holes of a connector portion of a
casing assembly of the branch joint box so as to be connected to terminals
of a mating connector which is connected to the connector portion of the
casing.
In the known branch joint box of this kind, a casing assembly 3 of the
branch joint box is formed by coupling upper and lower casings 1 and 2 of
identical shape as shown in FIGS. 1 to 3. A number of bus bars 4 are
accommodated in the casing assembly 3 in parallel and terminal portions 4b
and 4c extending from a coupling portion 4a of each bus bar 4 upwardly and
downwardly are, respectively, projected out of terminal holes 5a and 6a of
connector portions 5 and 6 disposed at upper and lower portions of the
casing assembly 3. In order to lock the upper and lower casings 1 and 2 to
each other, male and female locks 7 and 8 are provided on each of opposite
side faces of each of the upper and lower casings 1 and 2 such that the
male and female locks 7 and 8 on one of the opposite faces of each of the
upper and lower casings 1 and 2 are, respectively, disposed diagonally
relative to those on the other of the opposite faces of each of the upper
and lower casings 1 and 2 as shown in FIG. 2. By overturning one of the
upper and lower casings 1 and 2 upside down, the upper and lower casings 1
and 2 are coupled with each other. The upper and lower casings 1 and 2
are, respectively, partitioned by central partition walls 1a and 2a. The
connector portions 5 and 6 are laterally arranged in a plurality of rows,
for example, four rows shown in FIG. 1 at the upper and lower portions of
the casing assembly 3, respectively. A hollow in the casing assembly 3 is
used as a space 9 for accommodating the bus bars 4.
Each of the connector portions 5 has the terminal holes 5a of two rows and
each of the connector portions 6 has the terminal holes 6a of two rows. A
locking portion 10 is provided at one side of a central portion of each of
the connector portions 5 and 6. As shown in FIG. 2, a pitch A from a left
end of the upper casing 1 to the left terminal holes 5a-1 of the left end
connector portion 5 is different from a pitch A' from a right end of the
upper casing 1 to the right terminal holes 5a-2 of the right end connector
portion 5 due to provision of the locking portions 10. This difference
between the pitches A and A' cannot be reduced to less than 1.3 mm.
Meanwhile, a pitch B between the connector holes 5a of each connector
portion 5 and a pitch C between neighboring ones of the connector portions
5 are fixed.
Therefore, in the connector portions 6 of the lower casing 2 which is
coupled with the upper casing 1 by overturning the lower casing 2 upside
down, a distance from a right end of the lower casing 2 to the right end
terminal hole 6a-1 is equal to the pitch A, while a distance from a left
end of the lower casing 2 to the left end terminal hole 6a-2 is equal to
the pitch A'. Therefore, the terminal holes 5a and 6a of the upper and
lower casings 1 and 2, which confront each other, deviate from each other
through a distance of 1.3 mm (=A-A'). As a result, the bus bars 4 are
formed such that the terminal portions 4b and 4c deviate from each other
through a gap H of 1.3 mm (=A-A') at each of the coupling portions 4a.
The bus bars are formed by punching an electrically conductive metal plate
with a press and bending the metal plate. In case a number of the bus bars
of identical shape are required, the metal plate is continuously conveyed
so as to be sequentially subjected to pressing. If layout of the bus bars
4 is performed as shown in FIG. 4, the bus bar blank is taken most
efficiently from the metal plate when the terminal portions 4b and 4c
projecting towards the upper and lower casings 1 and 2, respectively
deviate from each other through the gap H. Namely, in regions S into which
the terminal portions 4b and 4c of the bus bars 4 do not project, terminal
portions 4b' and 4c' of neighboring bus bars 4' are arranged so as to
deviate from the terminal portions 4b and 4c. Meanwhile, in FIG. 4,
two-dot chain lines indicate bent portions.
However, in continuous press working of sequential feed, since the same
punching operation and the same bending operation should be performed on
an identical line in the direction of the arrow R for transporting the bus
bar blank, the bus bar blank cannot be taken from the metal plate by
layout of FIG. 4.
On the other hand, in case the terminal portions 4b' and 4c' of the
neighboring bus bars 4', which are arranged in the regions S so as to
deviate from the terminal portions 4b and 4c of the bus bars 4, are
eliminated as shown in FIG. 5, continuous press working of sequential feed
can be performed. However, in this case, a number of the regions S become
useless, thereby resulting in rise of cost of the bus bar blank.
Furthermore, in this case, in order to cut off a plurality of bus bars
from the bus bar blank subjected to the continuous working, a clearance C
acting as a cutting allowance is required to be provided between
neighboring ones of the bus bars 4, thus resulting in further
deterioration of yield of the bus bar blank.
SUMMARY OF THE INVENTION
Accordingly, an essential object of the present invention is to provide,
with a view to eliminating the above mentioned drawbacks of prior art
branch joint boxes, a branch joint box in which a casing assembly is
formed by upper and lower casings of an identical shape by overturning one
of the upper and lower casings and pitches of terminal holes of connector
portions of the upper and lower casings are provided symmetrically such
that upper and lower terminal portions of each of the bus bars can be
formed symmetrically. Therefore, the bus bars can be formed by continuous
press working of sequential feed without waste of a bus bar blank.
In order to accomplish this object of the present invention, a branch joint
box according to the present invention comprises: upper and lower casings
which have an identical shape and form a casing assembly by overturning
one of the upper and lower casings upside down; the upper and lower
casings being, respectively, provided with first connector portions and
second connector portions which are arranged in a plurality of rows and
have first terminal holes and second terminal holes, respectively; and bus
bars each of which has a coupling portion and first and second terminal
portions extending from opposite sides of the coupling portion,
respectively such that the coupling portion is accommodated in the casing
assembly; the first and second terminal portions being projected out of
the first and second terminal holes, respectively; the upper casing having
first locking portions disposed at one side of the first connector
portions, respectively, while the lower casing has second locking portions
engageable with the first locking portions and disposed at one side of the
second connector portions, respectively; wherein the first and second
terminal holes of the upper and lower casings are disposed symmetrically
and the first and second terminal portions extend from the opposite sides
of the coupling portion symmetrically in alignment with each other so as
to be inserted through the first and second terminal holes, respectively.
More specifically, in the first and second connector portions of the upper
and lower casings, the first and second locking portions disposed at one
side of the first and second connector portions make a distance from one
side face of each of the upper and lower casings to a corresponding
outermost one of the first and second terminal holes and a distance from
the other side face of each of the upper and lower casings to a
corresponding outermost one of the first and second terminal holes
different from each other. By this difference of the above distances, a
protrusion is formed on one outer side face of each of the upper and lower
casings adjacent to the other side of each of the first and second
connector portions. Therefore, a pitch from a distal end of the protrusion
to the corresponding outermost one of the first and second terminal holes
coincides with a pitch from the other outer side face of each of the upper
and lower casings to the corresponding outermost one of the first and
second terminal holes. Accordingly, when the upper and lower casing have
been coupled with each other by overturning one of the upper and lower
casings upside down, the first and second terminal holes of the upper and
lower casings are disposed symmetrically in alignment with each other.
Furthermore, the present invention provides a bus bar blank for forming the
bus bars accommodated in the branch joint box. Namely, the bus bar blank
comprises: a plurality of bus bars which are arranged in a plurality of
rows in a longitudinal direction of the bus bar blank and in each of which
a plurality of pairs of first and second terminal portions extend
longitudinally symmetrically in opposite directions from a laterally
extending coupling portion, respectively at a predetermined lateral
interval; first and second carrier portions which are, respectively,
coupled with opposite lateral sides of the coupling portion of each of the
bus bars; wherein the first and second terminal portions of the bus bars
of even rows are projected into regions into which the first and second
terminal portions of the bus bars of odd rows are not projected; wherein
the first and second terminal portions of the bus bars of odd rows are
aligned with each other and the first and second terminal portions of the
bus bars of even rows are aligned with each other such that the bus bar
blank can be subjected to continuous press working of sequential feed.
In the bus bar blank referred to above, the width of each of the first and
second carrier portions is increased such that a cutting line for
separating each of the bus bars from the bus bar blank in each of the
first and second carrier portions is set in hooked manner from a rear end
position of the coupling portion of a front one of neighboring bus bars to
a front end position of the coupling portion of a rear one of the
neighboring bus bars such that cut distal ends of each of the first and
second carrier portions project beyond the first and terminal portions of
the neighboring bus bars.
In the branch joint box of the present invention including the upper and
lower casings having an identical shape, the bus bars are initially
mounted in the lower casing in parallel such that the second terminal
portions of the bus bars are projected out of the second terminal holes of
the lower casing, respectively. At this time, the upper casing is
overturned upside down so as to be mounted on the lower casing such that
the first terminal portions of the bus bars are projected out of the first
terminal holes of the upper casing, respectively. As a result, the
coupling portions of the bus bars are accommodated between the upper and
lower casings. In this state, the first and second locking portions
provided on the upper and lower casings are brought into engagement with
each other.
In this branch joint box in which the upper and lower casings are coupled
with each other, since the opposite outermost terminal holes are disposed
symmetrically, the first and second terminal portions projecting from the
opposite sides of the coupling portion of each of the bus bars
symmetrically in alignment with each other can be mounted on the upper and
lower casings.
In the bus bars mounted on the branch joint box, since the terminal
portions can be symmetrically projected from the opposite sides of the
coupling portion of each of the bus bars in alignment with each other.
Therefore, since the bus bar blank for forming the bus bars enables
continuous press working of sequential feed, the bus bars can be arranged
at high yield in the bus bar blank.
Namely, in the bus bar blank in which the bus bars are arranged in a
plurality of rows in the longitudinal direction, since the terminal
portions of the bus bars of even rows are projected into the regions into
which the terminal portions of the bus bars of odd rows are not projected,
waste of material can be eliminated. In addition, since the terminal
portions of the bus bars of odd rows can be aligned with each other and
the terminal portions of the bus bars of even rows can be aligned with
each other, the bus bar blank can be subjected to continuous press working
of sequential feed.
Meanwhile, if the carrier portions disposed at the opposite sides of the
bus bar blank are cut in a hooked manner from the rear end portion of the
coupling portion of the front one of the neighboring bus bars to the front
end position of the coupling portion of the rear one of the neighboring
bus bars when the bus bars are separated from the bus bar blank subjected
to continuous press working of sequential feed, the cut distal ends of
each of the carrier portions can be projected beyond the first and second
terminal portions of the neighboring bus bars and thus, the first and
second terminal portions can be protected by projecting the carrier
portions.
BRIEF DESCRIPTION OF THE DRAWINGS
This object and features of the present invention will become apparent from
the following description taken in conjunction with the preferred
embodiment thereof with reference to the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of a prior art branch joint box
(already referred to);
FIG. 2 is a top plan view of an upper casing of the prior art branch joint
box of FIG. 1 (already referred to);
FIG. 3 is a bottom plan view of a lower casing of the prior art branch
joint box of FIG. 1 (already referred to);
FIG. 4 is a top plan view of a bus bar blank employed in the prior art
branch joint box of FIG. 1 (already referred to);
FIG. 5 is a top plan view of another bus bar blank employed in the prior
art branch joint box of FIG. 1 (already referred to);
FIG. 6 is an exploded perspective view of a branch joint box according to
the present invention;
FIG. 7 is a top plan view of an upper casing of the branch joint box of
FIG. 6;
FIG. 8 is a bottom plan view of a lower casing of the branch joint box of
FIG. 6;
FIG. 9 is a top plan view of a bus bar blank for bus bars employed in the
branch joint box of FIG. 6; and
FIG. 10 is a view similar to FIG. 9, particularly showing its modification.
Before the description of the present invention proceeds, it is to be noted
that like parts are designated by like reference numerals throughout
several views of the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, there is shown in FIGS. 6 to 8, a branch
joint box K according to one embodiment of the present invention. The
branch joint box K includes upper and lower casings 11 and 12 of identical
shape. The branch joint box K is different from a prior art branch joint
box of FIGS. 1 to 3 only in that a protrusion 20 is provided on one side
wall of each of the upper and lower casings 11 and 12 in the branch joint
box K. Since other constructions of the branch joint box are similar to
those of the prior art branch joint box, the detailed description is
abbreviated for the sake of brevity. Namely, male and female locks 7 and 8
are provided on each of opposite side faces of the upper and lower casings
11 and 12 such that the male and female locks 7 and 8 on one of the
opposite faces of each of the upper and lower casings 11 and 12 are,
respectively, disposed diagonally relative to those on the other of the
opposite faces of each of the upper and lower casings 11 and 12 as shown
in FIG. 6. On one face of a partition wall of each of the upper and lower
casings 11 and 12, which is oriented outwardly at the time of coupling of
the upper and lower casings 11 and 12, connector portions 5 and 6 are
laterally arranged in a plurality of rows, for example, four rows shown in
FIG. 6. Each of the connector portions 5 has terminal holes 5a of two
rows, while each of the connector portions 6 has terminal holes 6a of two
rows. Meanwhile, in FIG. 6, reference numeral 21 denotes an engageable
portion for mounting the branch joint box K on, for example, a body of a
motor vehicle.
A locking portion 10 is provided at one side of each of the connector
portions 5 and 6, i.e., at a left side of each of the connector portions 5
of the upper casing 11 and at a right side of each of the connector
portions 6 of the lower casing 12 so as to be fitted into a mating
connector. The protrusion 20 is provided on a right side wall of the upper
casing 11 and on a left side wall of the lower casing 12.
In the upper casing 11, a projecting distance W of the protrusion 20 is set
such that when a pitch from a left end of the upper casing 11 to the left
end terminal hole 5a-1 is a distance A, a pitch from a right end of the
upper casing 11 to the right end terminal hole 5a-2 is also the distance
A. Therefore, also in the lower casing 12 which is overturned upside down
relative to the upper casing 11, a pitch from a left end of the lower
casing 12, which is provided with the protrusion 20, to the left end
terminal hole 6a-2 is equal to the distance A and a pitch from a right end
of the lower casing 12 to the right end terminal hole 6a-1 is equal to the
distance A. As a result, the terminal holes 5a and 6a of the connector
portions 5 and 6 disposed at upper and lower portions of a casing 13 in
which the upper and lower casings 11 and 12 are coupled with each other
can be aligned with each other symmetrically. As shown in FIG. 6, a
plurality of bus bars 14 each having terminal portions 14b and 14c
extending upwardly and downwardly in alignment with each other from a
coupling portion 14a can be mounted in the casing 13 in which the upper
and lower casings 11 and 12 are coupled with each other.
The branch joint box K is assembled as follows. Initially, the bus bars 14
are mounted in the lower casing 12 in parallel such that the downwardly
extending terminal portions 14c of the bus bars 14 are projected out of
the terminal holes 6a of the connector portions 6 arranged in a plurality
of rows. In this state, the upper casing 11 is overturned upside down and
is brought into engagement with the lower casing 12. Thus, the upwardly
extending terminal portions 14b of the bus bars 14 are projected out of
the terminal holes 5a of the connector portions 5 formed in the upper
casing 11 such that the coupling portions 14a of the bus bars 14 are
accommodated between the upper and lower casings 11 and 12. In this state,
the male and female locks 7 and 8 provided on the upper casing 11 are,
respectively, brought into engagement with the female and male locks 8 and
7 provided on the lower casing 12.
The bus bars 14 are cut off from a bus bar blank 30 shown in FIG. 9. At
each of the bus bars 14, terminal portions 14b-1 and 14b-2 are spaced
laterally an interval L1 from each other and terminal portions 14c-1 and
14c-2 are also spaced laterally the interval L1 from each other. The
terminal portions 14b-1 and 14c-1 and the terminal portions 14b-2 and
14c-2 extend in the opposite longitudinal directions of the arrow Y in
alignment with each other from opposite ends of the coupling portion 14a
extending in the lateral directions of the arrow X. A pitch L2 between the
terminal portions 14b-1 and 14b-2, i.e., between the terminal portions
14c-1 and 14c-2 is equal to a pitch B between the terminal holes 5a of
each of the connector portions 5 and between the terminal holes 6a of each
of the connector portions 6.
As shown in FIG. 9, the bus bar blank 30 has a plurality of rows of the bus
bars 14 in the longitudinal direction of the arrow Y. Opposite ends of the
coupling portion 14a of each bus bar 14 are, respectively, coupled with
carrier portions 31A and 31B each having a width D. In the bus bars 14
arranged in a plurality of rows, the terminal portions of bus bars 14-II
of even rows are projected into regions into which the terminal portions
of bus bars 14-I of odd rows are not projected. Furthermore, the terminal
portions of the bus bars 14-I of odd rows are aligned with a longitudinal
line l-1, while the terminal portions of the bus bars 14-II of even rows
are aligned with a longitudinal line l-2.
The terminal portions of the bus bars 14-I and 14-II are aligned with the
longitudinal lines l-1 and l-2, respectively as described above.
Therefore, by punching and bending the electrically conductive material
for the bus bar blank with a press of sequential feed while the
electrically conductive material is being transported continuously in the
longitudinal directions of the arrow Y, it becomes possible to
continuously form the terminal portions.
FIG. 10 shows a bus bar blank 30' which is a modification of the bus bar
blank 30 of FIG. 9. In the bus bar blank 30', each of carrier portions
31A' and 31B' disposed at opposite ends of the coupling portion 14a has a
width D' larger than the width D of each of the carrier portions 31A and
31B. In the bus bars 14 of neighboring ones of a plurality of rows when
the carrier portions 31A' and 31B' are made wider as described above, the
carrier portions 31A' and 31B' can be cut in hooked manner along cutting
lines 40 from a rear end position P1 of the coupling portion 14a of the
bus bar 14-I of the upstream row to a front end position P2 of the
coupling portion 14a of the bus bar 14-II of the downstream row as shown
in FIG. 10. When a bus bar set having an arbitrary number of the bus bars
14 is obtained from the bus bar blank 30' by cutting the carrier portions
31A' and 31B', a cut end of each of the carrier portions 31A' and 31B'
projects beyond a distal end of each of the terminal portions 14b and 14c
at all times and thus, the projecting terminal portions 14b and 14c of the
bus bars 14 can be protected.
As is clear from the foregoing description of the branch joint box of the
present invention, since the terminal holes of the connector portions
provided on the upper and lower casings are disposed symmetrically in the
casing assembly in which one of the upper and lower casings of identical
shape is overturned upside down, the terminal portions extending in
alignment with each other symmetrically from the opposite sides of each of
the coupling portions of the bus bars can be fitted into the terminal
holes. Therefore, since the terminal portions can be extended in alignment
with each other symmetrically from the opposite sides of each of the
coupling portions in the bus bars employed in the branch joint box, the
bus bar can be obtained at high yield from the bus bar blank for the bus
bars through continuous press working of sequential feed. Namely, in the
bus bars of neighboring ones of a plurality of rows, the terminal portions
of the bus bars of one of the neighboring rows are projected into the
region into which the terminal portions of the bus bars of the other of
the neighboring rows are not projected, thereby resulting in reduction of
waste of material of the bus bar blank. Furthermore, since the terminal
portions of odd and even rows in the bus bar blank can be aligned with the
first and second longitudinal lines, respectively, the bus bar blank can
be subjected to continuous press working of sequential feed.
Meanwhile, when the bus bars are separated from the bus bar blank by
cutting the bus bar blank after continuous press working of sequential
feed referred to above, the carrier portions disposed at the opposite
sides of the bus bar blank in the bus bars of neighboring ones of a
plurality of rows can be cut in hooked manner from the rear end position
of the coupling portion of the bus bar of the upstream row to the front
end position of the coupling portion of the bus bar of the downstream row.
As a result, the distal end of each of the carrier portions can be
projected beyond the terminal portions of the bus bars after cutting and
thus, the terminal portions can be protected by the projecting carrier
portions.
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